The device of this invention relates generally to the field of lubrication. Specifically the instant invention relates to an apparatus for applying low volumes of lubricants to machinery, primarily cutting tools, so that only an amount of lubricant sufficient to properly enhance the performance of the cutting tool is applied.
The main purpose of using a lubricant is to reduce friction. This is because friction increases wear on machinery. The most destructive product of friction is heat. The use of lubricants allows a machine operator to avoid heat damage to his machinery. For example, cutting tools may be used on a particular workpiece for a variety of operations. If no lubrication is used then friction between the cutting tool and the workpiece will normally produce a tremendous amount of heat that can result in damage not only to the cutting tool but also to the workpiece. Because of the ability of lubricants to reduce friction they are sometimes referred to as coolants.
Because the area between a cutting tool and workpiece is the only area where lubrication is necessary to reduce friction it is an objective of the instant invention to provide only enough lubricant to coat the portion of the cutting tool in contact with the workpiece. This eliminates waste of lubricant that can occur in other lubricating methods like flood lubrication.
In flood lubrication a relatively large volume of lubricant is applied to the cutting tool and workpiece. This results in lubricant that is not used between the cutting tool and the workpiece being wasted and also requires, when the workpiece is to undergo a subsequent finishing processes like anodizing or plating, that the workpiece be cleaned; usually with solvents. It is further required that excess liquid be collected, and either re-used or disposed of in an approved manner. All of this creates costs which it is desirable to avoid.
Appropriately, it is another objective of the instant invention to apply lubricant in low volume amounts that are essentially consumed during the manufacturing process so that it is not necessary to clean the workpiece after the cutting tool has worked upon it. The reduction or elimination of a cleaning step in the manufacturing process has the advantage of eliminating or greatly reducing the need for solvents or other materials that may be required to prepare the workpiece for subsequent manufacturing processes and thus the need or cost of disposing of those materials can also be reduced or eliminated.
Still another objective of the instant invention is to create a system that can be filled at a much greater rate than the ultimate very small delivery rate, to avoid long set-up times and pre-filled delivery lines required by prior art systems.
Further, it is an objective of the instant invention to:
1. Provide a lubricant delivery system that is able to fill a new liquid delivery line with liquid in a short time by continuous operation of the pump and rapid opening and closing on the liquid solenoid valve.
2. Provide a lubricant delivery system that does not lose its prime when empty.
3. Provide a lubricant delivery system having flow restriction means in the delivery line of the device that can be quickly changed to give different flow delivery rates for the same timer setting or settings.
4. Deliver only an amount of lubricant sufficient to effectively lubricate a cutting tool so that it is not necessary to have to pre-wash the workpiece to remove excess lubricant before anodizing or plating.
5. Be able to engage with an outside controller to pump according to the start of operation of the machine tool or automatic machinery, or to use the limit switch of a machine tool.
The above objectives are fulfilled by the disclosed system.
The inventor knows of no prior art device or structure which has the same structure as the instant invention. U.S. Pat. No. 4,345,668 (Gaunt) discloses a low flow rate lubricating apparatus. However, the structure of Gaunt is not the structure of the instant invention. The Gaunt apparatus requires the use of pulses of air controlled by an "air logic unit". The instant invention does not have this structure. U.S. Pat. No. 3,888,420 (Boelkins), like Gaunt, requires that the liquid lubricant be applied by pulses of air supplied to cause the pump of Boelkins to operate through one stroke of the metering device with each pulse of air. The instant invention does not function this way nor does it have this structure. It is an objective of this invention to provide a lubricant delivery system in which the pump does not depend upon a pulsed air supply.